1 / 13

Enhancing Weather Forecasting Through COSMO-LEPS at 7 km

This feasibility study explores the potential of COSMO-LEPS at 7 km (cleps_7) to improve mesoscale weather forecasting by increasing horizontal resolution. The transition from 10 km to 7 km aims to provide a more detailed description of weather processes while maintaining competitiveness against ECMWF EPS. The new system offers enhanced capabilities with a higher resolution grid structure, albeit at higher costs and run times. Future plans include testing the impacts of the new system, utilizing soil moisture analysis, and optimizing post-processing methods. This study seeks to refine model perturbations, analyze snow patterns, and enhance ensemble forecasts. Collaboration and exchange of information within the SRNWP group are encouraged to further develop and apply these advancements in weather forecasting.

thomasmsmith
Download Presentation

Enhancing Weather Forecasting Through COSMO-LEPS at 7 km

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. WG 4 activities

  2. 1. COSMO LEPS

  3. Feasibility study of COSMOLEPS at 7 km (cleps_7) • “Keep the pace” with deterministic model (x~ 2-3 km): if the gap in resolutions between deterministic and probabilistic systems is too large, the two systems go for different solutions (that is, they forecast different weather!). Motivations: Provide a more detailed description of mesoscale processes by incresing the horizontal resolution. Do not lose a “reasonable advantage” against ECMWF EPS, which will go to x=25 km during 2009. from 10 to 7 km (plus small domain extensions) does not seem a lot

  4. COSMO-LEPS at 7 km (cleps_7): the answer to forecasters’ dream? New system x = 7 km z = 40 ML t = 72 s ngp = 510x405x40 = 8.262.000 fcst range = 132h cost = 1925 BU x run elapsed time = 138 min Present system x = 10 km z = 40 ML t = 90 s ngp = 306x258x40 = 3.157.920 fcst range = 132h cost = 640 BU x run elapsed time = 45 min … cleps_7 is about 3 times more expensive than the present configuration new computer at ECMWF being installed Computer resources for each ECMWF member state will increase by a factor of 5 (five)  and ….

  5. The dream is possible COSMO-LEPS 10 km COSMO-LEPS 7 km • the grid of cleps_7 would be almost identical to that of COSMO-EU, this making easier and cleaner the use of initial fields provided by DWD (e.g. soil moisture analysis).

  6. Future plans (2008 and 2009) • test the use of the Soil Moisture Analysis fields provided by DWD; • run cleps_7 for ~ 40 days in autumn 2008 and assess the impact; • within TIGGE-LAM, develop coding of COSMO-LEPS output files in GRIB2 format; • migration to the new machine at ECMWF; • use a better snow analysis (possibly provided by DWD or Meteoswiss); • extend the cluster analysis so as to consider not only ECMWF EPS, but also UKMO MOGREPS as global ensemble providing ic’s and bc’s (first tests); • implement cosmoleps_7; • gaining from COSMO-SREPS experience, introduce more model perturbations; • test COSMO-LEPS nested on the under-development ECMWF EDA over MAP D‑PHASE period; • optimise use of reforecasts + calibration of wind gust; • support CONSENS + verification

  7. 2. Postprocessing • Provide standard interface for internal postprocessing • WG6 WG4: Provide standard internal postprocessing methods (i.e. formula catalog) • Instability indices • Front parameter • Synthetic satellite images • … • Exchange external postprocessing methods • KF, MOS on wind, wind gusts • …

  8. mm/24h COSMO-2 RADAR 3. Use and interpretation of models Forecasters: we all started to use WRF for precipitation!

  9. 3. Use and interpretation of NWP models • Serious problems with “non-equilibrium convection cases ». Neither the 7km (parametrised convection) nor the 2km (explicit deep convection) predict precipitation correctly (even yes or no). • Who to blame? • The bad model(s)? • The forecasters overconfident in model(s)?

  10. The problem Quality of models Expectations from models 1960 1970 1980 2000 2010 1990

  11. Expectations / promises • Small grid spacing  high resolution forecast • Good (perfect) timing • Desire for sophisticated parameters: • Surface temperature • Rainfall • Cloudiness • Fog • Wind gusts • ….. • Expectations: from forecasters • Promises: from modellers

  12. Discussion points • What is really the quality of a model? • Which model is better? • In which situation? • For which parameter? • … • In a convective situation, do we look a the model rainfall pattern or a TS index? Or synoptics? • How does it compare with a statistical postprocessing on a global model? • Conditional verification can (must) be used • How can forecasters specify the conditions (weather classification, stability, season,…) • How can these informations be communicated?

  13. WG4: Interpretation and applications Discussion on these topic also started (recently) within SRNWP • Catalog and exchange of posprocessing methods • Listing and exchange of end-user applications (agriculture, aviation,…) • Use and interpretation of models? I am open to any collaborative suggestions for activities in this WG.

More Related